Orthostatic hypotension is low blood pressure that occurs when a person stands up. It results in decreased blood flow to the brain.
When a person goes from sitting or lying to a standing position, gravity can cause blood to pool in the lower half of the body. This can lower the blood pressure. However, the body has many ways to compensate for this, such as the heart pumping harder or the blood vessels constricting.
In various conditions, the body is unable to prevent abnormally low blood pressure from happening when a person stands up. This can lead to symptoms and is called orthostatic hypotension.
Symptoms of orthostatic hypotension occur when a person stands up. They may include: headacheneck pain or shoulder paindimming, blurring, or loss of visiondizzinessweaknesslightheadednessconfusionfalling downfainting, also called syncope
Orthostatic hypotension has many possible causes, including: dehydration, often from excessive vomiting, or severe diarrhea decreased blood volume, which can occur with excessive bleedingdrugs or medications, such as alcohol, the blood pressure medication prazosin (i.e., Minipress), or the diuretic called furosemide (i.e., Lasix)prolonged bed restold age, which can decrease the body's natural ability to maintain the blood pressure when a person stands updamage to the nervous system, such as that from diabetes, Parkinson's disease, or spinal cord injury heart conditions, such as a heart attack, congestive heart failure, or a problem with a valve in the heart called aortic stenosis anemia, that is, a low red blood cell countblood vessel problems, such as severe varicose veins low adrenal hormone levels, also called adrenal insufficiency
Other causes are also possible. Sometimes, no cause can be found.
Prevention of orthostatic hypotension is related to the cause. Making sure to get enough fluids can help prevent cases due to dehydration. Avoiding certain drugs can prevent cases from this cause. Avoiding prolonged bed rest can help prevent this cause. Many cases cannot be prevented.
The healthcare professional often makes this diagnosis when the individual becomes lightheaded as he or she sits up following the lying-down portion of a physical exam. To confirm the diagnosis, the professional can measure the blood pressure while the person is lying down, and then (carefully) when the person stands up.
Other tests may be needed to determine the cause of the orthostatic hypotension. For example, a blood test called a cortisol level can help detect low adrenal hormone levels. A blood sugar level can help diagnose diabetes. An imaging test of the heart called echocardiography can help diagnose heart failure or aortic stenosis. Other tests may also be used, depending on the suspected cause.
If someone with orthostatic hypotension faints when he or she stands up, there is a potential for injury. Most long-term effects are related to the cause. For example, a spinal cord injury can leave someone with permanent numbness or paralysis. Cases due to dehydration or drugs are usually treatable and often have no long-term effects.
Orthostatic hypotension is not contagious, and poses no risk to others.
Treatment is usually directed at the cause of the orthostatic hypotension. If dehydration is the cause, fluids can be given. If a medication is the cause, the medication can be stopped or the dose lowered. If a heart condition is the cause, a person may need medication or surgery to treat it.
In cases that cannot be treated directly, such as nervous system damage or old age, medication may be used to keep the blood pressure up. Salt tablets, support stockings for the legs, medication called corticosteroids, and other treatments may be used.
It is important for a person with orthostatic hypotension to get up slowly and have something or someone to hold onto when standing. If symptoms occur, the person should sit back down.
Side effects depend on the treatment used for the orthostatic hypotension. For example, corticosteroids may cause osteoporosis, mood swings, and high blood sugar levels. Surgery can be complicated by bleeding, infection, or reactions to anesthesia.
The success of treatment and the need for follow-up depend on the cause of the orthostatic hypotension. For example, those who developed this condition due to a medication often need no further treatment or monitoring when the medication is stopped. Those with nervous system damage or heart disease may need lifelong monitoring and treatment.
Repeated measurements of the blood pressure while lying down, sitting, and standing are often used for monitoring. Any medications used may need monitoring, which can include blood tests. The underlying cause may also need monitoring. For example, those with diabetes need to check their blood sugar levels regularly. Any new or worsening symptoms should be reported to the healthcare professional.
The Merck Manual, 1995, Berkow et al.